INFLUENCE OF 'CERTAIN ELEMENTS ON STEEL.
EFFECT OF SULPHUR ON BASIC STEEL.
The heats were classified according to their sulphur content, as shown in Table XVII-W and in Fig. XVIKF. The lines are irregular and indeterminate,, indicating a very small value for this element.
EFFECT OF CARBON UPON BASIC STEEL.
The effect of carbon was found, as in the case of acid steels, by allowing for phosphorus and manganese in the groups given in Table XVII-0. The data are given in Table XVII-X and in Fig. XVII-GL The line indicates a value of 770 Ib. for each 0.01 per cent, of carbon and it intersects the zero ordinate at 41,500 pounds.
TABLE XVII-X. Effect of Carbon upon Basic Steel.
NOTE.—In calculating the last column a value of 1000 pounds is given to 0,01 per cent, of phosphorus; the manganese is rated as shown in Table XVI1-V.
Class. Chemical composition ; per cent. Ultimate strength ; pounds per square incn.
Carbon. Phosphorus. Manganese. Actual records. After dedtict-Ing for phosphorus and manganese.
Basic test-bars ; carbon by combustion. 0.0978 0.1639 0.2115 0.2403 0.2681 0.3081 0.3582 0.0094 0.0107 0.0113 0.0110 0.0109 0.0108 0.0113 0.366 0.450 0.465 0.471 0.470 0.466 0.469 50834 57001 61502 64086 66297 69626 74203 49036 53621 57501 59805 61841 64994 69118
It has already been explained that any change in the value of manganese affects the tangent of the carbon-line, thereby affecting the value found for a unit of that element; and as manganese has been given a slightly. higher value in basic than in acid steel, it would naturally follow that the result for carbon would be lower in the basic than in the acid steel. To find how much this change in the value of manganese affected the carbon determination, the experiment was tried of correcting the line of basic, according to the values of manganese found for acid steel. The result showed a value of '810 Ib. for O.OJ per cent, of carbon, instead of 770 Ib. as found by the above special investigation. Inasmuch as the acid